Incandescent lamp.



A. SWAN INOANDESGENT LAMP.

nrmonmn rxmin Jun 7, 1900 905,478. Patented Dec. 1,1908.

Fig. I. v

Wfmzsscs INVEHTOR.

UNITED. STATES- -P aTENT orrron.

. ALFRED swan, or NEW YORK, N. V'Y., AssIGNoa To GENERAL ELECTRIC COMPANY, A

- CORPORATION OF NEW YQRK.

INCANDESCENT Specification of Letters Patent.

Patented. Dec.- 1, 1908.

application filed June 7, 1905. Serial No. acacia.

To all whom it may concern:

Be it known that I, ALFRED SWAN, a subject of the King of Great Britain, residing at New York in the county and State of New York, have inventedcertain new and useful Improvements in Incandescent Lamps, of which the following is a specification.

This invention relates to incandescent lamps and refers more particularly to the bases for such lamps and the method of connecting the leading-in wires of the lamp to the contacts of the base.

An incandescent lamp base as commonly constructed consists of two contacts held in proper relation and insulated from each other by a button or web of insulating material. Porcelain and plaster-of-paris have been used extensively as the insulating maproof and air-tight.

In order to connect the leading-in wires of the lamp to the contacts of the base the usual practice has been to provide openings through one or both of the contacts so that a leadin -in wire may be threaded through the opening when the base is to be cemented to the lamp bulb and afterwards soldered to the outer side of the contact to make electrical connection thereto. Thus an Edison type of 1am base consists of a threaded metallic shel and a metallic center contact united by insulating material and the center contact usually has an opening therethrough. Vhen the base is to be applied to a bulb one of the leading-in wires is bent down along the bulb so that it may afterwards be soldered to the edgeof the shell and the other leading-in Wire is inserted through the opening in the center contact. The base is then cemented to the bulb and afterwards the leading-in wire is soldered to the center con tact on the outsidethereof. This solder on the outside of the lamp base has always been considered as detracting from the appearance of the finished product and furthermore the terminal of a socket or receptacle usually bears on the solder and it is considered ob-v for connecting the leading-in wire to the under side of the center contact so that the solder does not show at all from the outside and connection is made with the contact direct and not through the solder used in connecting the leading-in wire thereto.

In accordance with my invention, I form the base with a cavity therein and an open- .ingthrough the base from the bottom of this cavity. In basing a lamp one of the leading-in wires is threaded through this opening and when the base is secured to the bulb the end of the wire is soldered to'the under side of a center contact outside tlie base. The extra length of wire necessary to permit this is th n pushed back and curled within the cavity until the contact issupported against the insulating web and the connection thereto concealed within the base. Preferably the cavit is partly or entirely filled with cement w ich assists in holding the parts in their proper relation. The cavity in the base should be formed to provide a seat for the center contact of such size that when the contact rests thereon its surface is fi'ush with the surface of the base in order thatnothing can catch on the contact and pull it out. The leading-in wire is. stifi' enough to hold the contact in position Within the cavity and if the cavity is filled with cementthere is little danger of the contact ever becoming displaced.

The novel features which I believe to be characteristic of my invention will be defi-' nitely indicated in the claims appended hereto. 7

The details of construction of my proved lamp base'and the method of applying the base to a lamp bulb will be better understood by reference to the following description taken in connection with the accompanying drawings which show one embodiment of my invention and in which Figure l is a section of the lamp base; Fig. 2 is an elevation of the same applied to a lamp bulb showing the end of oneof the leadin -in wiresextending throu hthe base and so dered to the under side 0 the centercontact; and Fig. 3 is a sectional elevation and Fig. 4 a pleted lain In the rawings I have shown my inrprovements in connection with a lamp base of the Edison type but I Wish it understood that my invention is not limited in thisztw perspective view of the com- .tact instead of through the solder used in spect but isapplicable also to other types of ,lamp bases which have gone into'commercial use. The base consists of a threaded metaL lic shell 1 which is partially closed at one end by a web of insulating material 2 in the center of which a cavity 3 is formed; an opening 4 extends from the bottom of the cavity 3 to the interior of the base and the top of cavity 3 isso formed that a center contact will fit tightly therein with its surface flush with thevsurface of the Web. This base is preferably made by inserting the shell 1 in a suitably-shaped mold, dropping a charge of glass reduced to a fluid state therein, and pressing the glass around the flange on the end of the shell, since in this way a' joint is formed between the shell and the glass which is very strong and practicaliy-moistureproof and air-tight.

in order to secure the base upon the neck of the bulb 5 oneof the leading-in wires 6 is bent back along the bulb and the other leading-in wire 7 is threaded through the opening 4 in the base. A suitable cementing compound 8 is then introduced into the base, the leadingin wire is severed at the proper point and'its end soldered to the inside of the shell 1 near the edge, as shown in Fig. 3. The base is then pressed down over the neck of the bulb where it is held tightly in place until the cementing compound has hardened. The end of the leading-in wire 7 extending through the base is then soldered to the under side of the center contact 9, as shown in Fig. 2. This contact preferably consists of a circular piece of thin sheet-metal. The extra length of the leading-in wire 7 necessary to permit soldering its end to the under side of the center contact in this way is then pushed back and curled within the cavity 3 in the web 2 of insulating material until the center contact 9 is seated in the shallow depression at the top of the cavity in proper position with its surface flush with the surface of the glass or other material and the connection to the contact concealed within the base. The wire 7 is still enough to hold the contact 9 in position; if desired, however, the cavity 3 may be partly or entirely filled with cement 10 before the contact 9 is seated in position so that the contact will be held more firmly. The surface of the contact 9 being flush with that of the insulating web 2 in the completed lamp, as shown in Fig. 4, a smooth exterior is presented -and there is little or no danger of anything catching on the edge of the contact 9 and pulling it away from its seat. In the finished lamp madeas described herein, there is no solder on the exterior of the base which therefore presents a better appearance than those formerly used and contact is made direct with the center conconnccting the leading-in wire to the conta t. i

coarse trated and described herein but that various modifications can be made in the construction and the method described without departing from the spiritof my invention.

What I claim as new, and desire to secure by Letters Patent of the United States, is,

1. An incandescent lamp having a base comprising a shell and an insulatin web with an opening through it, a leading-in wire extending through and movable in said opening and long enough to extend beyond the web, a center contact soldered to the end of the leading-in wire, and means for bolding said contact in engagement with the base.

2. An incandescent lamp having a-base comprising a shell and an insulating web with an opening through it, a lead1ng-1n wire extending through and movable in said opening and long enough to extend beyond the web, and a center contact soldered to the end of the' leading-in wire, said wire being cemented to the web to hold said contact in position on the web.

3. An incandescent lamp having a base comprising a shell and an insulating web with a de ression on the outer side and an opening t rough the web into said depression, a leading-in wire extending through and movable in said opening and long enough to extend beyond the web, a center contact the same size as the depression soldered to the end of said wire, and means for holding said contact in said depression flush with the outer surface of the web.

Y 4: An incandescent lamp comprising a base having a shell, a web of insulating material at one end thereof having a cavity therein, a contact covering said cavity with its outside surface flush with the outside sur face of the web, a bulb to which the base is secured havin a leading-in wire connected to the under side of said contact, and means for securing the wire to the web to hold the contact in position.

5. An incandescent lamp comprising a base having a shell, a web of insulating material at one end thereof, a contact supported by said web, and a bulb to which the base is secured having a leading-in wire a portion of which is curled up in a cavity in the web, the end of said wire being connected to the under side of the contact.

6. An incandescent lamp comprising a base having a shell, a web of insulating matcrial at one end thereof having a cavity therein, a contact supported by said web,

' and a bulb to which the base is secured havbase having a metallic shell, a we r of .th

,7 cavity therein,

and havin its outer surface flush with the outer snr'ace of said web, and a bulb to which the base'is secured having a leading-in wire with its end connected to the under side e contact and a portion near its. end

curled up within said cavity.

8. An incandescent 1am com rising a base having a metallic shel a we of insulating material secured thereto having a cavity therein and a contact supported by said web, a bulb to which the base is secured having a leadin -in wire with its end connected to the un er side of the contact and a a contact covering said cavity the lead wire curled portion near its end curled within said cavity, and cement in said cavity holding the leading-in wire.

9. In anincandescent lamp, a bulb having leading-in wires extendin therefrom, an a base attached to said bul outside thereof and a hole leading from the cavity through the web, a contact set in said and comprising a a shell to which one of the leading-in wires is attached, a web of insulating material in said shell, said web having a cavity on the web and having one of the leading-in wires attached to its inner side, and cement in the cavity in the web for holding the portion of up therein.

In witness whereof,

. ALFRED SWAN.

Witnesses:

S. N. WHiTEHEAD, JOHN E. MrroHEnL, Jr.

l I have hereunto set w my hand this first day of June, 1905. 

